The goal of this application is to examine the brain basis, via functional magnetic resonance imaging (fMRI), of normal age-associated changes in cognitive and memory performance. The proposed study differs from prior studies of aging in several ways as it takes advantage of current knowledge in cognitive neuroscience and recent advances in fMRI to examine the relation between memory abilities and the functional status of memory systems in the brain across the human life span. It examines multiple forms of memory that are known to be differentially affected by aging within the same individual brains; executive and non-executive aspects of working memory, semantic memory, explicit memory, and implicit memory (repetition priming). It includes a wide range of older people, from young-old to old-old, in order to examine the brain basis of variation in age-associated memory performance. It exploits recent advances in fMRI data acquisition and analysis, including single-trial analyses that reveal more information than standard brain imaging methods. It contrasts age-associated effects on memory systems and memory abilities with the effects of normal child development and of individual differences among young adults. For each of three studies, the investigators propose to scan: a) 10 older subjects 60-69 years old; 10 older subjects 70-79 years old; 10 older subjects 80-89 years old; b) 10 children 7-9 years old; 10 children 11-13 years old; and 10 children 16-18 years old; and c) 20 young adult subjects, ages 20-22, 10 with a relatively high working memory capacity and 10 with a relatively low working memory capacity. The proposed studies ought to reveal a great deal about the brain basis of human memory and changes in that basis across the life span that is highly relevant to disorders of memory that occur in many neurological and psychiatric diseases in both older adults and children, including Alzheimer's disease, Parkinson's disease, and learning disabilities.